Abstract / Summary
BackgroundThis study investigated the associations of multiregional macular and peripapillary OCTA metrics and systemic hematologic biomarkers with 12-month diabetic retinopathy progression and evaluated whether their combination improved prognostic discrimination.MethodsThis single-center longitudinal cohort study included 55 adults with type 2 diabetes and established DR, contributing 108 eyes. Baseline macular and peripapillary vessel density parameters were obtained by OCTA, and peripheral blood laboratory markers were measured. DR progression was defined as worsening by at least two steps on the Diabetic Retinopathy Severity Scale (DRSS) at 12 months. Generalized estimating equation (GEE) models were used to account for within-participant inter-eye correlation. Univariable and multivariable GEE analyses were conducted to identify baseline factors independently associated with DR progression. Receiver operating characteristic analysis was performed for the individual markers and combined models.ResultsDuring follow-up, 52 eyes (48.15%) showed DR progression and 56 eyes (51.85%) did not. In the final multivariable GEE model, higher temporal peripapillary VD (adjusted OR, 0.88; 95%CI, 0.81–0.95), higher deep VD within the 1–3-mm parafoveal annulus (adjusted OR, 0.86; 95% CI, 0.78–0.96; P = 0.01), and higher lymphocyte count (adjusted OR, 0.31; 95% CI, 0.11–0.87; P = 0.03) were associated with lower odds of progression. The AUCs were 0.72 for temporal peripapillary VD, 0.70 for deep parafoveal VD, and 0.70 for lymphocyte count. The OCTA model combining the two VD parameters achieved an AUC of 0.80 (95% CI, 0.72–0.88), whereas the OCTA-plus-lymphocyte model achieved an AUC of 0.84 (95% CI, 0.77–0.92). After internal validation by participant-level cluster bootstrap (500 resamples), the optimism-corrected AUC of the OCTA-plus-lymphocyte model was 0.83 (apparent AUC 0.84; optimism ≤0.012), and the 10-fold participant-level cross-validated AUC was 0.81 for the combined model vs. 0.78 for the OCTA-only model.ConclusionLower temporal peripapillary VD, lower deep parafoveal VD, and lower peripheral blood lymphocyte count were associated with 12-month DR progression. Their combination demonstrated the highest apparent discrimination in this cohort. As this is a single-center exploratory cohort without external validation, these discriminative estimates should be regarded as apparent, and the model requires confirmation in larger, multicenter longitudinal studies before clinical application.